A History of Violence (18)

These are among the themes addressed in A History of Violence, though this time Cronenberg has stripped away the sci-fi trappings and extravagant effects of old. Despite the fact Josh Olson's script is based upon a graphic novel, the movie has a lean, realistic texture, more rooted in the here and now than those dark parables the Cronenberg name was made on.

The title, which makes it sound like a documentary, seems to augur portentous generalities, whereas its story deals with something compellingly particular: a man, his family, their bond with each other. Set in Millbrook, Indiana, a rural backwater where folks greet one another on the main street, it concerns Tom Stall (Viggo Mortensen), his lawyer wife Edie (Maria Bello) and their two children.

Tom and Edie are on the brink of middle age, yet like to roll back the years; when the kids aren't around, she dresses up as a high-school cheerleader to give their sex life an extra boost. The kinky playfulness says: "we're not hidebound, we can surprise one another." If only they knew. This picture of relaxed togetherness is suddenly turned violently askew when the diner Tom runs is held up by a couple of thugs whose murderous handiwork we have seen up close in the film's (superb) prologue.

Seeing that his staff and customers are in mortal danger, Tom snaps into action and by a courageous manoeuvre overpowers the two gunmen and kills them. By the next day the media is all over the story and Tom is suddenly the have-a-go-hero. The publicity makes him uncomfortable, as it would any modest, retiring sort. But something much worse follows in its wake.

A week or two later a stranger named Fogarty (Ed Harris) arrives in town, and calls at the diner. Tom doesn't know him, but he knows Tom, or rather, he thinks he knows Tom, back when his name was Joey Cusack - the same Joey who scarred him down the left side of his face. It transpires that Fogarty is part of an Irish mob Joey once ran with in Philadelphia, and now he's come for payback. Tom looks nonplussed, and we brace ourselves for a variation on Hitchcock's "wrong man" theme. The town sheriff warns the newcomer off, but Fogarty, with his goons and his black sedan, isn't going to budge until Tom comes clean.

This is where the film enters its most gripping phase, and Mortensen's performance is crucial. Ever since his Aragorn in The Lord of The Rings Mortensen has been a go-to man for understated virility and integrity that simply cannot accommodate the possibility of deceit. But this isn't Middle Earth, it's the Midwest, where a man just might come to bury his old identity and start anew.

What Mortensen does brilliantly is to keep us guessing. At first we are outraged on his behalf that anyone could conceivably mistake him for a killer - "crazy Joey", of all the nerve! - and even in the face of Fogarty's unwavering conviction the benefit of the doubt sides with Tom. But then we start to see him through his wife's eyes, and the appraising looks Bello turns on him suggest there might be a tranche of his past she knows nothing about. And how about that name, "Stall"? Wouldn't that be the perfect choice of a man trying to delay his own unmasking? Cronenberg constructs this enigma of identity that feels absolutely convincing.

By degrees he insinuates the idea of violence as an inescapable destiny, redolent of Clint Eastwood's reformed killer in Unforgiven finding himself pulled back into the old ways. That Tom's teenage son Jack (Ashton Holmes) has pit-bull instincts - the scene in which he suddenly attacks the school bully is genuinely shocking - actually presses the argument further that violence might be genetic, a theme that transfused Paul Schrader's sombre father-and-son picture, Affliction.

There's also a disturbing shift in Tom and Edie's physical relationship: the implication is that the man she did that cheerleader-in-the-bedroom stuff for is not the same one she has rough sex with after the crisis hits home. The trauma of lives split in two drives Cronenberg's best work - think of Jeremy Irons' twins in Dead Ringers, and Christopher Walken's transformation from coma victim to clairvoyant in The Dead Zone.

There is something of greatness in this director, and only the last act of A History of Violence stops it just short of those earlier achievements. The film's austere atmosphere of dread, marvellously sustained for over an hour, is subtly poisoned by the late entrance of William Hurt as a Philadelphian mob boss.

The one thing it doesn't need is a grandstanding turn, yet Hurt attempts to provide one in his camp impersonation of cruelty. I suspect his intention is to steal the movie, and instead he almost runs it off the road. Cronenberg restores his authority with a beautifully ambiguous final scene: a family sits down to dinner, and from their tight, wordless communion one can't tell if the presiding mood is closer to Norman Rockwell or to Norman Bates.